Apparatus for controlling movement of knitting machine carrier friction boxes



Oct. 21, 1941. H. E. BAUN 2,260,162

APPARATUS FoE coNTRoLLING MOVEMENT oF KNITTING MACHINE CARRIER FRIcTIoN BOXES Filed Jan. 8, 1941 2 sheets-sheet 1 QM QNWWLM [Lf Il INVENTOR.

77' ANff.

oct. 21, 1941. H. E. BAUN 2,260,162

APPARATUS FOR CONTROLLING MOVEMENT OF KNITTING MACHINE CARRIER FRICTION BOXES Patented Oct. 21, 1941 APPARATUS FOR ofoN'rRoLIANG MOVE- MENT oF KNITTING MACHINE CARRIER FRJCTION BOXE S Hermann E. Baun, Indianapolis,` Ind.

Application January 8, 1941, Serial No. 373,658

(Cl. Gli-130) Claims.

This invention relates to apparatus for controlling movement of knitting machine carrier friction boxes.

In knitting machines 4used in the knitting of full-fashioned hosiery and other similar products there has been a tendency to increase the output by increasing the speed of operation. With the controlling mechanism heretofore in use for carrier friction box operation, the increased speeds have resulted in numerous diiculties due to shock at the limits of friction box travel and the difficulty of uniformly retarding the friction box movement with the variable limits employed for such movement.

The carrier friction box of a knitting machine of this type is reciprocated at a rapid rate by means of a friction drive connection of any suitable type. The friction box in turn moves the thread carriers from one edge of the work to the other and return. The length of travel of the friction box depends upon the width of the fabric in each course and this travel must be limited by definitely placed stop members which are moved inwardly from time to time as the work is narrowed by reducing the number of stitches. With the increased speed of operation, the shock occurring as the friction box is stopped causes an undesirable rebound of the thread carriers which draws an additional small amount of thread and forms an objectionable loop at the edge of the work. Retarding means heretofore employed to control the movement of the friction box near the end of its travel has not satisfactorily overcome the results of such shock. This is largely due to the fact that such devices have not exerted a uniform retarding force independent of the variations in the travel of the friction box due to the narrowing operation.

One object of the present invention is to provide means for controlling the travel of the friction box which is independent of the position of the limiting stops and thus provides uniform retardation throughout the forming of a piece of work of varying width, such as a stocking or similar fabric.

Another object of the invention is to provide controlling apparatus of this type in which the retarding action is uniform throughout that portion of each stroke of the friction box travel in which said force is applied.

Another object of the invention is to provide control apparatus of this type operable at both ends of the friction box travel and so arranged that the yielding movement of a contact mem- 55 known manner.

ber at one end of said travel resets a similar contact member in proper operative position to be effective at the opposite limit of the friction box travel. y

Other objects and features of the invention will be understood from the accompanying drawings and the following description and claims:

Fig. 1 is a plan View of a portion of a knitting machine to which the invention has been applied in one of its preferred forms and shows the friction box and associated parts. Fig. 2 is a front elevational view of the same. Fig. 3 is a side view with parts shown in section. Fig. 4 is a longitudinal sectional view through a buffer device forming part of the invention.

Referring now to the drawings illustrating a preferred form of the invention, there is shown therein a fixed shaft I0 which is suitably supported on the stationary frame of the knitting machine and which serves as a support and guiding means for the friction box and the associated stop members. A rectangular friction rod II is arranged generally parallel to the shaft IU and is reciprocated a fixed distance in each direction by well known mechanism, not shown. The distance of movement of the friction rod is greater than the greatest desired movement of the friction box. The friction box I 2 includes a portion I3 embracing the friction rod Il and carrying therein suitable friction plates frictionally engaging the rod l I and adapted to carry the friction box to right or left in the movement of said'rod until said friction box is stopped by a suitable means. The construction of said friction plates is well known in the art and requires no further description.

The friction box I2 has a. downwardly extending portion I4 terminating in a bearing I5 slidably mounted on the shaft I0. A buffer device I6, described in more detail hereinafter, is also mounted on the friction box I2. The friction box has formed in the upper surface thereof a guideway for a horizontal slide I1 and said guide- Way is covered by a plate I8 to retain said slide therein. At the rear of said slide there is provided a fitting I9 extending downwardly and having portions engaging opposite sides of a bar 20 which may be moved forwardly and backwardly, referring to Fig. 1, to move the slide I'l in and out. At its forward end the slide I'I is provided with a downwardly extending hook 2| adapted to enter the space between lugs 22 formed on carrier rods 23 which are slidably supported on the frame of the machine in a Well The carrier rods 23 extend the full length of the machine and each supports one thread carrier (not shown) for each section of the machine. The operation of the carriers, carrier rods 23 and slide I1 in response to automatic movement of the bar is well known in the art and formsno part of the present invention. It is sufficient to say that the bar 20 is automatically moved at the end of each course to place the finger 2| in engagement with the carrier rod 23 to be used in the knitting of the next course. An auxiliary finger 24 is also provided on the friction head to operate a fourth carrier rod if desired. When not in use said v.

linger is placed in the upraised position shown in the drawings.

At each side of the friction box there is provided a stop member 25 and each of said stop members is provided with a bearing portion 2.6-

slidably mounted on the stationary shaft lil. Said stop members are moved longitudinally on said' shaft by means of `rods 2l adjustably Secured thereto'and'operated ina-manner well known in theart. to vpositionsaid stop membersin accordance with the width of the fabric in eachY course and to move saidstop members when a .change in the width of fabric is to be made. The stop member 25 at the left of Figs. 1 and 2 is provided with an abutment `portion 28 adjustably mounted thereon and adapted to engage an abutment sur; face 29 formed on the body of theV friction head I2...` The stop member 25 ,at the right rof Figs. 1 and 2'isV provided with .a similarabutment member `.ill adapted .to engage an abutment surface 3l on the opposite Aend .of thefriction head l2. Engagement of the abutment portions 2 8 and 29 definitely limits the travel of the friction box tothe left` and similarly engagement of the abutment portions .3D and Si definitely limits travel lof the friction `box. to the right.

`Referring now more particularly to Fig. 4, in which there Visshovvn Vthe buffer device l5 carried by the friction box, said device includes .a central member-'5.2, having secured thereto at opposite ends a pair of `cylinders 4and having a central passage 34; connecting said cylinders. HA piston 3 5 .operates in one of the. cylinders y33 .and has secured 4thereto. a piston rod 3.5 slidablymounted ina-,cap 3l threadedly engaged ini the end .of the Cylinder 3,3. U.Said cap is providedwith a-ir passages 3S permitting entrance. and exit of air to the-portion of the cylinder 33 behind the piston 35.l Atthe Yopposite end .0f the device l5 there is provided a similar piston'SB, piston rod wand cap 41; The interior of the cylinders 33V adjacent the body portion 3 2 is filled with la suitable working fluid such as oil, air,-water or glycerine. Passage of said fluid fromgone of said .cylinders4 to the' other maybe controlled 'by a throttle valve IZ- threadedly engaged in a boss 43 secured to the body portion 32. Y Y Y Y 1 Abutments 4 4 andy45A are formed on the-stop members 2,5 at the left and rightof Figs. 1 and 2 respectively and are located in the paths of the pistori--rodshSS and 49, Near theend of each stroke -of the friction box one of said piston rods engages its associated abutment and is displaced therebywith respect to its associated cylinder to forcethe Working fluid through the passage-34 into vthe opposite cylinder.y The-force required to move the fluid through said passage serves toretard the movement of the friction box-and the entrance of said fluid to the opposite cylinder movesv the opposite piston land piston `rod outwardly. The overall distance between the outer ends of the piston rods 36 and 40.1is substantially uniform and is determined by the volume of the fluid contained in the cylinders.

In the operation of the apparatus the stops 25 are first set at the proper position to limit the travel of the friction box in accordance with the Width of fabric in the initial course of the Work. The friction rod Il is reciprocated and carries the friction box to right and left between the limits yset by said stops. As the Work is narrowed by reduction in the number of stitches, the stop members 25 are automatically moved inwardly to vary the travel of the friction box accordingly. The vtotal travel of the friction box, represented by the sum of dimensions Y and Y in Fig. 1, is thus a variable quantity. The total clearance betweenV the piston rods 36 and 40 and abutments 44 and 45, represented by the sum of dimensions X and X', varies by the same amount. This total clearance is determined by the amount of workingA fluid carried within the cylinders 33 and is so chosen that X plus X is less than Y plus Y' by .a predetermined amount A. At the -end of a stroke of the friction box to the right, dimensions X and Yare both zero. During the return stroke to the left, as shown in Fig. 1, X' and Y are equal and X plus A equals Y. Piston rod 35 thus strikes abutment 44 and Y equals A, no matter in what position the stop member 25 may be placed. `The retarding force is thus applied at a'f uniform distance from the end of the stroke ofthe `friction head independent of the length l.of said' stroke. The displacement ofv piston rod 36, during its retardijng action,- moves-piston 40 outwardly through the distance A so that the same relation holds true at the end of the right hand strokes of the friction box. Y

The retarding action of the buffer device 4B is due to the pressure required to force the working,V fluid through the restricted passage 34y and this force isuniform throughout the travel o f the friction box through the distance A. A'Ifhe amount of this force can be regulated by'adjustment of the throttle valve 4.2 and thevdistance through which said force is applied may be easily controlled by addingvtoor subtracting froml the Working fluid in the cylinders 33. The latter result may also-be Vobtained by adjusting the positions ofthe abutment members 28 and 30fwith respect tothe stop members 25 and by making a similar adjustment in the positions of the rods 2l with respect to said members.

From the foregoing description it willfbe apparent that the invention provides forl retarding the movement of the friction box at each end of its travel with a uniform force exerted through a uniform distance independent of the length of said travel.A Both the force applied and the distance through Which it is applied may be conveniently varied to suit different speeds andoperating conditions of Ythe apparatus. By this means the formationof undesirable loops on the edge of the work has been eliminated and Wear and tear on the mechanism has been greatly reduced. v n

'Ihe invention has beendescribed in one of its preferred forms, the detailsl of which may be varied by those skilled in the art Without departing from the scope thereof as denedin the appended claims.

VThe invention claimedis: l

1. In a knitting machine, a reciprocable friction box. stop members at each side thereof, said friction box and said stop members having mating `abutment portions unyieldingly engageable to definitelylimit the travel of said friction box in each direction, and said stop members being relatively movable to vary the limits of said travel, and yielding buffer means carried by said friction box and engaging said stop members to cushion the stopping action thereof, said buffer means engaging said stop members when the corresponding mating abutment portions are separated by a predetermined distance, irrespective of the position of said stop members.

2. In a knitting machine, a reciprocable friction box, stop members at each side thereof, said friction box and said stop members having mating abutment portions unyieldingly engageable to definitely limit the travel of said friction box in each direction. and said stop members being relatively movable to vary the limits of said travel, and yielding buffer means carried by said friction box and engaging said stop members to cushion the stopping action thereof, said buffer means engaging said stop members when the corresponding mating abutment portions are separated by a predetermined distance, irrespective of the position of said stop members, and being adapted to apply a substantially uniform retarding force during movement of said friction box through said predetermined distance.

3. In a knitting machine, a reciprocable friction box, stop members at each side thereof, said friction box and said stop members having mating abutment portions unyieldingly engageable to denitely limit the travel of said friction box in each direction, and said stop members being relatively movable to vary the limits of said travel, and a buffer device mounted on said friction box and having oppositely positioned contact members adapted to engage the respective stop members adjacent the opposite limits of friction box travel, each of said contact members engaging its respective stop member When the corresponding abutment members are a predetermined distance apart and each yieldingly applying a retarding force to the movement of said friction box, and said contact members being operatively connected whereby the yielding movement of one resets the other in position to engage its corresponding stop member at the proper point in the return travel of said friction box.

4. In combination with the friction box and movable stop members of a knitting machine, a buffer device mounted on said friction box, said device including a pair of oppositely positioned cylinders, a piston operating in each cylinder, a piston rod connected to each piston, said piston rods extending in opposite directions and being adapted to engage said stop members respectively adjacent the opposite limits of friction box travel, means forming a restricted passage for a Working fiuid between said cylinders, and throttling means in said passage for varying the resistance to flow of said fluid therethrough.

5. The combination With the reciprocating friction box of a kniting machine of stop members at each side thereof, said friction box and said stop members having mating abutment portions unyieldingly engageable to definitely limit the travel of said friction box in each direction, and said stop members being relatively movable to vary the limits of said travel, and a buffer device mounted on said friction box, said device including a pair of oppositely positioned cylinders, a piston operating in each cylinder, a piston rod connected to each piston, and means forming a restricted passage for a Working fluid between said cylinders, said piston rods extending in opposite directions to engage said stop members respectively adjacent the opposite limits of travel of said friction head, and each piston rod being displaceable by said engagement to force said working fluid from its associated cylinder to the other cylinder to exert a retarding force on the movement of said friction box and to reset the other piston rod in operative position.

HERMANN E. BAUN. 

